1 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
2 #![feature(associated_type_defaults)]
3 #![feature(control_flow_enum)]
4 #![feature(rustc_private)]
5 #![feature(try_blocks)]
6 #![feature(let_chains)]
7 #![recursion_limit = "256"]
8 #![deny(rustc::untranslatable_diagnostic)]
9 #![deny(rustc::diagnostic_outside_of_impl)]
16 use rustc_ast::MacroDef;
17 use rustc_attr as attr;
18 use rustc_data_structures::fx::FxHashSet;
19 use rustc_data_structures::intern::Interned;
21 use rustc_hir::def::{DefKind, Res};
22 use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdSet, CRATE_DEF_ID};
23 use rustc_hir::intravisit::{self, Visitor};
24 use rustc_hir::{AssocItemKind, HirIdSet, ItemId, Node, PatKind};
25 use rustc_middle::bug;
26 use rustc_middle::hir::nested_filter;
27 use rustc_middle::middle::privacy::{EffectiveVisibilities, Level};
28 use rustc_middle::span_bug;
29 use rustc_middle::ty::query::Providers;
30 use rustc_middle::ty::subst::InternalSubsts;
31 use rustc_middle::ty::{self, Const, DefIdTree, GenericParamDefKind};
32 use rustc_middle::ty::{TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
33 use rustc_session::lint;
34 use rustc_span::hygiene::Transparency;
35 use rustc_span::symbol::{kw, sym, Ident};
38 use std::marker::PhantomData;
39 use std::ops::ControlFlow;
40 use std::{cmp, fmt, mem};
43 FieldIsPrivate, FieldIsPrivateLabel, FromPrivateDependencyInPublicInterface, InPublicInterface,
44 InPublicInterfaceTraits, ItemIsPrivate, PrivateInPublicLint, ReportEffectiveVisibility,
48 ////////////////////////////////////////////////////////////////////////////////
49 /// Generic infrastructure used to implement specific visitors below.
50 ////////////////////////////////////////////////////////////////////////////////
52 /// Implemented to visit all `DefId`s in a type.
53 /// Visiting `DefId`s is useful because visibilities and reachabilities are attached to them.
54 /// The idea is to visit "all components of a type", as documented in
55 /// <https://github.com/rust-lang/rfcs/blob/master/text/2145-type-privacy.md#how-to-determine-visibility-of-a-type>.
56 /// The default type visitor (`TypeVisitor`) does most of the job, but it has some shortcomings.
57 /// First, it doesn't have overridable `fn visit_trait_ref`, so we have to catch trait `DefId`s
58 /// manually. Second, it doesn't visit some type components like signatures of fn types, or traits
59 /// in `impl Trait`, see individual comments in `DefIdVisitorSkeleton::visit_ty`.
60 trait DefIdVisitor<'tcx> {
63 fn tcx(&self) -> TyCtxt<'tcx>;
64 fn shallow(&self) -> bool {
67 fn skip_assoc_tys(&self) -> bool {
74 descr: &dyn fmt::Display,
75 ) -> ControlFlow<Self::BreakTy>;
77 /// Not overridden, but used to actually visit types and traits.
78 fn skeleton(&mut self) -> DefIdVisitorSkeleton<'_, 'tcx, Self> {
79 DefIdVisitorSkeleton {
81 visited_opaque_tys: Default::default(),
82 dummy: Default::default(),
85 fn visit(&mut self, ty_fragment: impl TypeVisitable<'tcx>) -> ControlFlow<Self::BreakTy> {
86 ty_fragment.visit_with(&mut self.skeleton())
88 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<Self::BreakTy> {
89 self.skeleton().visit_trait(trait_ref)
91 fn visit_projection_ty(&mut self, projection: ty::AliasTy<'tcx>) -> ControlFlow<Self::BreakTy> {
92 self.skeleton().visit_projection_ty(projection)
96 predicates: ty::GenericPredicates<'tcx>,
97 ) -> ControlFlow<Self::BreakTy> {
98 self.skeleton().visit_predicates(predicates)
102 struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
103 def_id_visitor: &'v mut V,
104 visited_opaque_tys: FxHashSet<DefId>,
105 dummy: PhantomData<TyCtxt<'tcx>>,
108 impl<'tcx, V> DefIdVisitorSkeleton<'_, 'tcx, V>
110 V: DefIdVisitor<'tcx> + ?Sized,
112 fn visit_trait(&mut self, trait_ref: TraitRef<'tcx>) -> ControlFlow<V::BreakTy> {
113 let TraitRef { def_id, substs, .. } = trait_ref;
114 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref.print_only_trait_path())?;
115 if self.def_id_visitor.shallow() { ControlFlow::CONTINUE } else { substs.visit_with(self) }
118 fn visit_projection_ty(&mut self, projection: ty::AliasTy<'tcx>) -> ControlFlow<V::BreakTy> {
119 let tcx = self.def_id_visitor.tcx();
120 let (trait_ref, assoc_substs) =
121 if tcx.def_kind(projection.def_id) != DefKind::ImplTraitPlaceholder {
122 projection.trait_ref_and_own_substs(tcx)
124 // HACK(RPITIT): Remove this when RPITITs are lowered to regular assoc tys
125 let def_id = tcx.impl_trait_in_trait_parent(projection.def_id);
126 let trait_generics = tcx.generics_of(def_id);
128 tcx.mk_trait_ref(def_id, projection.substs.truncate_to(tcx, trait_generics)),
129 &projection.substs[trait_generics.count()..],
132 self.visit_trait(trait_ref)?;
133 if self.def_id_visitor.shallow() {
134 ControlFlow::CONTINUE
136 assoc_substs.iter().try_for_each(|subst| subst.visit_with(self))
140 fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> ControlFlow<V::BreakTy> {
141 match predicate.kind().skip_binder() {
142 ty::PredicateKind::Clause(ty::Clause::Trait(ty::TraitPredicate {
146 })) => self.visit_trait(trait_ref),
147 ty::PredicateKind::Clause(ty::Clause::Projection(ty::ProjectionPredicate {
151 term.visit_with(self)?;
152 self.visit_projection_ty(projection_ty)
154 ty::PredicateKind::Clause(ty::Clause::TypeOutlives(ty::OutlivesPredicate(
157 ))) => ty.visit_with(self),
158 ty::PredicateKind::Clause(ty::Clause::RegionOutlives(..)) => ControlFlow::CONTINUE,
159 ty::PredicateKind::ConstEvaluatable(ct) => ct.visit_with(self),
160 ty::PredicateKind::WellFormed(arg) => arg.visit_with(self),
161 _ => bug!("unexpected predicate: {:?}", predicate),
167 predicates: ty::GenericPredicates<'tcx>,
168 ) -> ControlFlow<V::BreakTy> {
169 let ty::GenericPredicates { parent: _, predicates } = predicates;
170 predicates.iter().try_for_each(|&(predicate, _span)| self.visit_predicate(predicate))
174 impl<'tcx, V> TypeVisitor<'tcx> for DefIdVisitorSkeleton<'_, 'tcx, V>
176 V: DefIdVisitor<'tcx> + ?Sized,
178 type BreakTy = V::BreakTy;
180 fn visit_ty(&mut self, ty: Ty<'tcx>) -> ControlFlow<V::BreakTy> {
181 let tcx = self.def_id_visitor.tcx();
182 // InternalSubsts are not visited here because they are visited below
183 // in `super_visit_with`.
185 ty::Adt(ty::AdtDef(Interned(&ty::AdtDefData { did: def_id, .. }, _)), ..)
186 | ty::Foreign(def_id)
187 | ty::FnDef(def_id, ..)
188 | ty::Closure(def_id, ..)
189 | ty::Generator(def_id, ..) => {
190 self.def_id_visitor.visit_def_id(def_id, "type", &ty)?;
191 if self.def_id_visitor.shallow() {
192 return ControlFlow::CONTINUE;
194 // Default type visitor doesn't visit signatures of fn types.
195 // Something like `fn() -> Priv {my_func}` is considered a private type even if
196 // `my_func` is public, so we need to visit signatures.
197 if let ty::FnDef(..) = ty.kind() {
198 tcx.fn_sig(def_id).visit_with(self)?;
200 // Inherent static methods don't have self type in substs.
201 // Something like `fn() {my_method}` type of the method
202 // `impl Pub<Priv> { pub fn my_method() {} }` is considered a private type,
203 // so we need to visit the self type additionally.
204 if let Some(assoc_item) = tcx.opt_associated_item(def_id) {
205 if let Some(impl_def_id) = assoc_item.impl_container(tcx) {
206 tcx.type_of(impl_def_id).visit_with(self)?;
210 ty::Alias(ty::Projection, proj) => {
211 if self.def_id_visitor.skip_assoc_tys() {
212 // Visitors searching for minimal visibility/reachability want to
213 // conservatively approximate associated types like `<Type as Trait>::Alias`
214 // as visible/reachable even if both `Type` and `Trait` are private.
215 // Ideally, associated types should be substituted in the same way as
216 // free type aliases, but this isn't done yet.
217 return ControlFlow::CONTINUE;
219 // This will also visit substs if necessary, so we don't need to recurse.
220 return self.visit_projection_ty(proj);
222 ty::Dynamic(predicates, ..) => {
223 // All traits in the list are considered the "primary" part of the type
224 // and are visited by shallow visitors.
225 for predicate in predicates {
226 let trait_ref = match predicate.skip_binder() {
227 ty::ExistentialPredicate::Trait(trait_ref) => trait_ref,
228 ty::ExistentialPredicate::Projection(proj) => proj.trait_ref(tcx),
229 ty::ExistentialPredicate::AutoTrait(def_id) => {
230 ty::ExistentialTraitRef { def_id, substs: InternalSubsts::empty() }
233 let ty::ExistentialTraitRef { def_id, substs: _ } = trait_ref;
234 self.def_id_visitor.visit_def_id(def_id, "trait", &trait_ref)?;
237 ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) => {
238 // Skip repeated `Opaque`s to avoid infinite recursion.
239 if self.visited_opaque_tys.insert(def_id) {
240 // The intent is to treat `impl Trait1 + Trait2` identically to
241 // `dyn Trait1 + Trait2`. Therefore we ignore def-id of the opaque type itself
242 // (it either has no visibility, or its visibility is insignificant, like
243 // visibilities of type aliases) and recurse into bounds instead to go
244 // through the trait list (default type visitor doesn't visit those traits).
245 // All traits in the list are considered the "primary" part of the type
246 // and are visited by shallow visitors.
247 self.visit_predicates(ty::GenericPredicates {
249 predicates: tcx.explicit_item_bounds(def_id),
253 // These types don't have their own def-ids (but may have subcomponents
254 // with def-ids that should be visited recursively).
270 | ty::GeneratorWitness(..) => {}
271 ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
272 bug!("unexpected type: {:?}", ty)
276 if self.def_id_visitor.shallow() {
277 ControlFlow::CONTINUE
279 ty.super_visit_with(self)
283 fn visit_const(&mut self, c: Const<'tcx>) -> ControlFlow<Self::BreakTy> {
284 let tcx = self.def_id_visitor.tcx();
285 tcx.expand_abstract_consts(c).super_visit_with(self)
289 fn min(vis1: ty::Visibility, vis2: ty::Visibility, tcx: TyCtxt<'_>) -> ty::Visibility {
290 if vis1.is_at_least(vis2, tcx) { vis2 } else { vis1 }
293 ////////////////////////////////////////////////////////////////////////////////
294 /// Visitor used to determine impl visibility and reachability.
295 ////////////////////////////////////////////////////////////////////////////////
297 struct FindMin<'a, 'tcx, VL: VisibilityLike> {
299 effective_visibilities: &'a EffectiveVisibilities,
303 impl<'a, 'tcx, VL: VisibilityLike> DefIdVisitor<'tcx> for FindMin<'a, 'tcx, VL> {
304 fn tcx(&self) -> TyCtxt<'tcx> {
307 fn shallow(&self) -> bool {
310 fn skip_assoc_tys(&self) -> bool {
317 _descr: &dyn fmt::Display,
318 ) -> ControlFlow<Self::BreakTy> {
319 if let Some(def_id) = def_id.as_local() {
320 self.min = VL::new_min(self, def_id);
322 ControlFlow::CONTINUE
326 trait VisibilityLike: Sized {
328 const SHALLOW: bool = false;
329 fn new_min(find: &FindMin<'_, '_, Self>, def_id: LocalDefId) -> Self;
331 // Returns an over-approximation (`skip_assoc_tys` = true) of visibility due to
332 // associated types for which we can't determine visibility precisely.
336 effective_visibilities: &EffectiveVisibilities,
338 let mut find = FindMin { tcx, effective_visibilities, min: Self::MAX };
339 find.visit(tcx.type_of(def_id));
340 if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
341 find.visit_trait(trait_ref);
346 impl VisibilityLike for ty::Visibility {
347 const MAX: Self = ty::Visibility::Public;
348 fn new_min(find: &FindMin<'_, '_, Self>, def_id: LocalDefId) -> Self {
349 min(find.tcx.local_visibility(def_id), find.min, find.tcx)
352 impl VisibilityLike for Option<Level> {
353 const MAX: Self = Some(Level::Direct);
354 // Type inference is very smart sometimes.
355 // It can make an impl reachable even some components of its type or trait are unreachable.
356 // E.g. methods of `impl ReachableTrait<UnreachableTy> for ReachableTy<UnreachableTy> { ... }`
357 // can be usable from other crates (#57264). So we skip substs when calculating reachability
358 // and consider an impl reachable if its "shallow" type and trait are reachable.
360 // The assumption we make here is that type-inference won't let you use an impl without knowing
361 // both "shallow" version of its self type and "shallow" version of its trait if it exists
362 // (which require reaching the `DefId`s in them).
363 const SHALLOW: bool = true;
364 fn new_min(find: &FindMin<'_, '_, Self>, def_id: LocalDefId) -> Self {
365 cmp::min(find.effective_visibilities.public_at_level(def_id), find.min)
369 ////////////////////////////////////////////////////////////////////////////////
370 /// The embargo visitor, used to determine the exports of the AST.
371 ////////////////////////////////////////////////////////////////////////////////
373 struct EmbargoVisitor<'tcx> {
376 /// Effective visibilities for reachable nodes.
377 effective_visibilities: EffectiveVisibilities,
378 /// A set of pairs corresponding to modules, where the first module is
379 /// reachable via a macro that's defined in the second module. This cannot
380 /// be represented as reachable because it can't handle the following case:
382 /// pub mod n { // Should be `Public`
383 /// pub(crate) mod p { // Should *not* be accessible
384 /// pub fn f() -> i32 { 12 } // Must be `Reachable`
390 macro_reachable: FxHashSet<(LocalDefId, LocalDefId)>,
391 /// Previous visibility level; `None` means unreachable.
392 prev_level: Option<Level>,
393 /// Has something changed in the level map?
397 struct ReachEverythingInTheInterfaceVisitor<'a, 'tcx> {
398 level: Option<Level>,
399 item_def_id: LocalDefId,
400 ev: &'a mut EmbargoVisitor<'tcx>,
403 impl<'tcx> EmbargoVisitor<'tcx> {
404 fn get(&self, def_id: LocalDefId) -> Option<Level> {
405 self.effective_visibilities.public_at_level(def_id)
408 /// Updates node level and returns the updated level.
409 fn update(&mut self, def_id: LocalDefId, level: Option<Level>) -> Option<Level> {
410 let old_level = self.get(def_id);
411 // Visibility levels can only grow.
412 if level > old_level {
413 self.effective_visibilities.set_public_at_level(
415 || ty::Visibility::Restricted(self.tcx.parent_module_from_def_id(def_id)),
428 level: Option<Level>,
429 ) -> ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
430 ReachEverythingInTheInterfaceVisitor {
431 level: cmp::min(level, Some(Level::Reachable)),
437 // We have to make sure that the items that macros might reference
438 // are reachable, since they might be exported transitively.
439 fn update_reachability_from_macro(&mut self, local_def_id: LocalDefId, md: &MacroDef) {
440 // Non-opaque macros cannot make other items more accessible than they already are.
442 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
443 let attrs = self.tcx.hir().attrs(hir_id);
444 if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
448 let macro_module_def_id = self.tcx.local_parent(local_def_id);
449 if self.tcx.opt_def_kind(macro_module_def_id) != Some(DefKind::Mod) {
450 // The macro's parent doesn't correspond to a `mod`, return early (#63164, #65252).
454 if self.get(local_def_id).is_none() {
458 // Since we are starting from an externally visible module,
459 // all the parents in the loop below are also guaranteed to be modules.
460 let mut module_def_id = macro_module_def_id;
462 let changed_reachability =
463 self.update_macro_reachable(module_def_id, macro_module_def_id);
464 if changed_reachability || module_def_id == CRATE_DEF_ID {
467 module_def_id = self.tcx.local_parent(module_def_id);
471 /// Updates the item as being reachable through a macro defined in the given
472 /// module. Returns `true` if the level has changed.
473 fn update_macro_reachable(
475 module_def_id: LocalDefId,
476 defining_mod: LocalDefId,
478 if self.macro_reachable.insert((module_def_id, defining_mod)) {
479 self.update_macro_reachable_mod(module_def_id, defining_mod);
486 fn update_macro_reachable_mod(&mut self, module_def_id: LocalDefId, defining_mod: LocalDefId) {
487 let module = self.tcx.hir().get_module(module_def_id).0;
488 for item_id in module.item_ids {
489 let def_kind = self.tcx.def_kind(item_id.owner_id);
490 let vis = self.tcx.local_visibility(item_id.owner_id.def_id);
491 self.update_macro_reachable_def(item_id.owner_id.def_id, def_kind, vis, defining_mod);
493 if let Some(exports) = self.tcx.module_reexports(module_def_id) {
494 for export in exports {
495 if export.vis.is_accessible_from(defining_mod, self.tcx) {
496 if let Res::Def(def_kind, def_id) = export.res {
497 if let Some(def_id) = def_id.as_local() {
498 let vis = self.tcx.local_visibility(def_id);
499 self.update_macro_reachable_def(def_id, def_kind, vis, defining_mod);
507 fn update_macro_reachable_def(
514 let level = Some(Level::Reachable);
516 self.update(def_id, level);
519 // No type privacy, so can be directly marked as reachable.
520 DefKind::Const | DefKind::Static(_) | DefKind::TraitAlias | DefKind::TyAlias => {
521 if vis.is_accessible_from(module, self.tcx) {
522 self.update(def_id, level);
526 // Hygiene isn't really implemented for `macro_rules!` macros at the
527 // moment. Accordingly, marking them as reachable is unwise. `macro` macros
528 // have normal hygiene, so we can treat them like other items without type
529 // privacy and mark them reachable.
530 DefKind::Macro(_) => {
531 let item = self.tcx.hir().expect_item(def_id);
532 if let hir::ItemKind::Macro(MacroDef { macro_rules: false, .. }, _) = item.kind {
533 if vis.is_accessible_from(module, self.tcx) {
534 self.update(def_id, level);
539 // We can't use a module name as the final segment of a path, except
540 // in use statements. Since re-export checking doesn't consider
541 // hygiene these don't need to be marked reachable. The contents of
542 // the module, however may be reachable.
544 if vis.is_accessible_from(module, self.tcx) {
545 self.update_macro_reachable(def_id, module);
549 DefKind::Struct | DefKind::Union => {
550 // While structs and unions have type privacy, their fields do not.
552 let item = self.tcx.hir().expect_item(def_id);
553 if let hir::ItemKind::Struct(ref struct_def, _)
554 | hir::ItemKind::Union(ref struct_def, _) = item.kind
556 for field in struct_def.fields() {
557 let field_vis = self.tcx.local_visibility(field.def_id);
558 if field_vis.is_accessible_from(module, self.tcx) {
559 self.reach(field.def_id, level).ty();
563 bug!("item {:?} with DefKind {:?}", item, def_kind);
568 // These have type privacy, so are not reachable unless they're
569 // public, or are not namespaced at all.
572 | DefKind::ConstParam
573 | DefKind::Ctor(_, _)
578 | DefKind::ImplTraitPlaceholder
583 | DefKind::LifetimeParam
584 | DefKind::ExternCrate
586 | DefKind::ForeignMod
588 | DefKind::InlineConst
593 | DefKind::Generator => (),
598 impl<'tcx> Visitor<'tcx> for EmbargoVisitor<'tcx> {
599 type NestedFilter = nested_filter::All;
601 /// We want to visit items in the context of their containing
602 /// module and so forth, so supply a crate for doing a deep walk.
603 fn nested_visit_map(&mut self) -> Self::Map {
607 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
608 let item_level = match item.kind {
609 hir::ItemKind::Impl { .. } => {
610 let impl_level = Option::<Level>::of_impl(
611 item.owner_id.def_id,
613 &self.effective_visibilities,
615 self.update(item.owner_id.def_id, impl_level)
617 _ => self.get(item.owner_id.def_id),
620 // Update levels of nested things.
622 hir::ItemKind::Enum(ref def, _) => {
623 for variant in def.variants {
624 let variant_level = self.update(variant.def_id, item_level);
625 if let Some(ctor_def_id) = variant.data.ctor_def_id() {
626 self.update(ctor_def_id, item_level);
628 for field in variant.data.fields() {
629 self.update(field.def_id, variant_level);
633 hir::ItemKind::Impl(ref impl_) => {
634 for impl_item_ref in impl_.items {
635 if impl_.of_trait.is_some()
636 || self.tcx.visibility(impl_item_ref.id.owner_id).is_public()
638 self.update(impl_item_ref.id.owner_id.def_id, item_level);
642 hir::ItemKind::Trait(.., trait_item_refs) => {
643 for trait_item_ref in trait_item_refs {
644 self.update(trait_item_ref.id.owner_id.def_id, item_level);
647 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
648 if let Some(ctor_def_id) = def.ctor_def_id() {
649 self.update(ctor_def_id, item_level);
651 for field in def.fields() {
652 let vis = self.tcx.visibility(field.def_id);
654 self.update(field.def_id, item_level);
658 hir::ItemKind::Macro(ref macro_def, _) => {
659 self.update_reachability_from_macro(item.owner_id.def_id, macro_def);
661 hir::ItemKind::ForeignMod { items, .. } => {
662 for foreign_item in items {
663 if self.tcx.visibility(foreign_item.id.owner_id).is_public() {
664 self.update(foreign_item.id.owner_id.def_id, item_level);
669 hir::ItemKind::OpaqueTy(..)
670 | hir::ItemKind::Use(..)
671 | hir::ItemKind::Static(..)
672 | hir::ItemKind::Const(..)
673 | hir::ItemKind::GlobalAsm(..)
674 | hir::ItemKind::TyAlias(..)
675 | hir::ItemKind::Mod(..)
676 | hir::ItemKind::TraitAlias(..)
677 | hir::ItemKind::Fn(..)
678 | hir::ItemKind::ExternCrate(..) => {}
681 // Mark all items in interfaces of reachable items as reachable.
683 // The interface is empty.
684 hir::ItemKind::Macro(..) | hir::ItemKind::ExternCrate(..) => {}
685 // All nested items are checked by `visit_item`.
686 hir::ItemKind::Mod(..) => {}
687 // Handled in `rustc_resolve`.
688 hir::ItemKind::Use(..) => {}
689 // The interface is empty.
690 hir::ItemKind::GlobalAsm(..) => {}
691 hir::ItemKind::OpaqueTy(ref opaque) => {
692 // HACK(jynelson): trying to infer the type of `impl trait` breaks `async-std` (and `pub async fn` in general)
693 // Since rustdoc never needs to do codegen and doesn't care about link-time reachability,
694 // mark this as unreachable.
695 // See https://github.com/rust-lang/rust/issues/75100
696 if !opaque.in_trait && !self.tcx.sess.opts.actually_rustdoc {
697 // FIXME: This is some serious pessimization intended to workaround deficiencies
698 // in the reachability pass (`middle/reachable.rs`). Types are marked as link-time
699 // reachable if they are returned via `impl Trait`, even from private functions.
700 let exist_level = cmp::max(item_level, Some(Level::ReachableThroughImplTrait));
701 self.reach(item.owner_id.def_id, exist_level).generics().predicates().ty();
705 hir::ItemKind::Const(..)
706 | hir::ItemKind::Static(..)
707 | hir::ItemKind::Fn(..)
708 | hir::ItemKind::TyAlias(..) => {
709 if item_level.is_some() {
710 self.reach(item.owner_id.def_id, item_level).generics().predicates().ty();
713 hir::ItemKind::Trait(.., trait_item_refs) => {
714 if item_level.is_some() {
715 self.reach(item.owner_id.def_id, item_level).generics().predicates();
717 for trait_item_ref in trait_item_refs {
719 let mut reach = self.reach(trait_item_ref.id.owner_id.def_id, item_level);
720 reach.generics().predicates();
722 if trait_item_ref.kind == AssocItemKind::Type
723 && !tcx.impl_defaultness(trait_item_ref.id.owner_id).has_value()
732 hir::ItemKind::TraitAlias(..) => {
733 if item_level.is_some() {
734 self.reach(item.owner_id.def_id, item_level).generics().predicates();
737 // Visit everything except for private impl items.
738 hir::ItemKind::Impl(ref impl_) => {
739 if item_level.is_some() {
740 self.reach(item.owner_id.def_id, item_level)
746 for impl_item_ref in impl_.items {
747 let impl_item_level = self.get(impl_item_ref.id.owner_id.def_id);
748 if impl_item_level.is_some() {
749 self.reach(impl_item_ref.id.owner_id.def_id, impl_item_level)
758 // Visit everything, but enum variants have their own levels.
759 hir::ItemKind::Enum(ref def, _) => {
760 if item_level.is_some() {
761 self.reach(item.owner_id.def_id, item_level).generics().predicates();
763 for variant in def.variants {
764 let variant_level = self.get(variant.def_id);
765 if variant_level.is_some() {
766 for field in variant.data.fields() {
767 self.reach(field.def_id, variant_level).ty();
769 // Corner case: if the variant is reachable, but its
770 // enum is not, make the enum reachable as well.
771 self.reach(item.owner_id.def_id, variant_level).ty();
773 if let Some(ctor_def_id) = variant.data.ctor_def_id() {
774 let ctor_level = self.get(ctor_def_id);
775 if ctor_level.is_some() {
776 self.reach(item.owner_id.def_id, ctor_level).ty();
781 // Visit everything, but foreign items have their own levels.
782 hir::ItemKind::ForeignMod { items, .. } => {
783 for foreign_item in items {
784 let foreign_item_level = self.get(foreign_item.id.owner_id.def_id);
785 if foreign_item_level.is_some() {
786 self.reach(foreign_item.id.owner_id.def_id, foreign_item_level)
793 // Visit everything except for private fields.
794 hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(ref struct_def, _) => {
795 if item_level.is_some() {
796 self.reach(item.owner_id.def_id, item_level).generics().predicates();
797 for field in struct_def.fields() {
798 let field_level = self.get(field.def_id);
799 if field_level.is_some() {
800 self.reach(field.def_id, field_level).ty();
804 if let Some(ctor_def_id) = struct_def.ctor_def_id() {
805 let ctor_level = self.get(ctor_def_id);
806 if ctor_level.is_some() {
807 self.reach(item.owner_id.def_id, ctor_level).ty();
813 let orig_level = mem::replace(&mut self.prev_level, item_level);
814 intravisit::walk_item(self, item);
815 self.prev_level = orig_level;
818 fn visit_block(&mut self, b: &'tcx hir::Block<'tcx>) {
819 // Blocks can have public items, for example impls, but they always
820 // start as completely private regardless of publicity of a function,
821 // constant, type, field, etc., in which this block resides.
822 let orig_level = mem::replace(&mut self.prev_level, None);
823 intravisit::walk_block(self, b);
824 self.prev_level = orig_level;
828 impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
829 fn generics(&mut self) -> &mut Self {
830 for param in &self.ev.tcx.generics_of(self.item_def_id).params {
832 GenericParamDefKind::Lifetime => {}
833 GenericParamDefKind::Type { has_default, .. } => {
835 self.visit(self.ev.tcx.type_of(param.def_id));
838 GenericParamDefKind::Const { has_default } => {
839 self.visit(self.ev.tcx.type_of(param.def_id));
841 self.visit(self.ev.tcx.const_param_default(param.def_id));
849 fn predicates(&mut self) -> &mut Self {
850 self.visit_predicates(self.ev.tcx.predicates_of(self.item_def_id));
854 fn ty(&mut self) -> &mut Self {
855 self.visit(self.ev.tcx.type_of(self.item_def_id));
859 fn trait_ref(&mut self) -> &mut Self {
860 if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
861 self.visit_trait(trait_ref);
867 impl<'tcx> DefIdVisitor<'tcx> for ReachEverythingInTheInterfaceVisitor<'_, 'tcx> {
868 fn tcx(&self) -> TyCtxt<'tcx> {
875 _descr: &dyn fmt::Display,
876 ) -> ControlFlow<Self::BreakTy> {
877 if let Some(def_id) = def_id.as_local() {
878 if let (ty::Visibility::Public, _) | (_, Some(Level::ReachableThroughImplTrait)) =
879 (self.tcx().visibility(def_id.to_def_id()), self.level)
881 self.ev.update(def_id, self.level);
884 ControlFlow::CONTINUE
888 ////////////////////////////////////////////////////////////////////////////////
889 /// Visitor, used for EffectiveVisibilities table checking
890 ////////////////////////////////////////////////////////////////////////////////
891 pub struct TestReachabilityVisitor<'tcx, 'a> {
893 effective_visibilities: &'a EffectiveVisibilities,
896 impl<'tcx, 'a> TestReachabilityVisitor<'tcx, 'a> {
897 fn effective_visibility_diagnostic(&mut self, def_id: LocalDefId) {
898 if self.tcx.has_attr(def_id.to_def_id(), sym::rustc_effective_visibility) {
899 let mut error_msg = String::new();
900 let span = self.tcx.def_span(def_id.to_def_id());
901 if let Some(effective_vis) = self.effective_visibilities.effective_vis(def_id) {
902 for level in Level::all_levels() {
903 let vis_str = match effective_vis.at_level(level) {
904 ty::Visibility::Restricted(restricted_id) => {
905 if restricted_id.is_top_level_module() {
906 "pub(crate)".to_string()
907 } else if *restricted_id == self.tcx.parent_module_from_def_id(def_id) {
908 "pub(self)".to_string()
910 format!("pub({})", self.tcx.item_name(restricted_id.to_def_id()))
913 ty::Visibility::Public => "pub".to_string(),
915 if level != Level::Direct {
916 error_msg.push_str(", ");
918 error_msg.push_str(&format!("{:?}: {}", level, vis_str));
921 error_msg.push_str("not in the table");
923 self.tcx.sess.emit_err(ReportEffectiveVisibility { span, descr: error_msg });
928 impl<'tcx, 'a> Visitor<'tcx> for TestReachabilityVisitor<'tcx, 'a> {
929 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
930 self.effective_visibility_diagnostic(item.owner_id.def_id);
933 hir::ItemKind::Enum(ref def, _) => {
934 for variant in def.variants.iter() {
935 self.effective_visibility_diagnostic(variant.def_id);
936 if let Some(ctor_def_id) = variant.data.ctor_def_id() {
937 self.effective_visibility_diagnostic(ctor_def_id);
939 for field in variant.data.fields() {
940 self.effective_visibility_diagnostic(field.def_id);
944 hir::ItemKind::Struct(ref def, _) | hir::ItemKind::Union(ref def, _) => {
945 if let Some(ctor_def_id) = def.ctor_def_id() {
946 self.effective_visibility_diagnostic(ctor_def_id);
948 for field in def.fields() {
949 self.effective_visibility_diagnostic(field.def_id);
956 fn visit_trait_item(&mut self, item: &'tcx hir::TraitItem<'tcx>) {
957 self.effective_visibility_diagnostic(item.owner_id.def_id);
959 fn visit_impl_item(&mut self, item: &'tcx hir::ImplItem<'tcx>) {
960 self.effective_visibility_diagnostic(item.owner_id.def_id);
962 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
963 self.effective_visibility_diagnostic(item.owner_id.def_id);
967 //////////////////////////////////////////////////////////////////////////////////////
968 /// Name privacy visitor, checks privacy and reports violations.
969 /// Most of name privacy checks are performed during the main resolution phase,
970 /// or later in type checking when field accesses and associated items are resolved.
971 /// This pass performs remaining checks for fields in struct expressions and patterns.
972 //////////////////////////////////////////////////////////////////////////////////////
974 struct NamePrivacyVisitor<'tcx> {
976 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
977 current_item: LocalDefId,
980 impl<'tcx> NamePrivacyVisitor<'tcx> {
981 /// Gets the type-checking results for the current body.
982 /// As this will ICE if called outside bodies, only call when working with
983 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
985 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
986 self.maybe_typeck_results
987 .expect("`NamePrivacyVisitor::typeck_results` called outside of body")
990 // Checks that a field in a struct constructor (expression or pattern) is accessible.
993 use_ctxt: Span, // syntax context of the field name at the use site
994 span: Span, // span of the field pattern, e.g., `x: 0`
995 def: ty::AdtDef<'tcx>, // definition of the struct or enum
996 field: &'tcx ty::FieldDef,
997 in_update_syntax: bool,
1003 // definition of the field
1004 let ident = Ident::new(kw::Empty, use_ctxt);
1005 let hir_id = self.tcx.hir().local_def_id_to_hir_id(self.current_item);
1006 let def_id = self.tcx.adjust_ident_and_get_scope(ident, def.did(), hir_id).1;
1007 if !field.vis.is_accessible_from(def_id, self.tcx) {
1008 self.tcx.sess.emit_err(FieldIsPrivate {
1010 field_name: field.name,
1011 variant_descr: def.variant_descr(),
1012 def_path_str: self.tcx.def_path_str(def.did()),
1013 label: if in_update_syntax {
1014 FieldIsPrivateLabel::IsUpdateSyntax { span, field_name: field.name }
1016 FieldIsPrivateLabel::Other { span }
1023 impl<'tcx> Visitor<'tcx> for NamePrivacyVisitor<'tcx> {
1024 type NestedFilter = nested_filter::All;
1026 /// We want to visit items in the context of their containing
1027 /// module and so forth, so supply a crate for doing a deep walk.
1028 fn nested_visit_map(&mut self) -> Self::Map {
1032 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1033 // Don't visit nested modules, since we run a separate visitor walk
1034 // for each module in `effective_visibilities`
1037 fn visit_nested_body(&mut self, body: hir::BodyId) {
1038 let old_maybe_typeck_results =
1039 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1040 let body = self.tcx.hir().body(body);
1041 self.visit_body(body);
1042 self.maybe_typeck_results = old_maybe_typeck_results;
1045 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1046 let orig_current_item = mem::replace(&mut self.current_item, item.owner_id.def_id);
1047 intravisit::walk_item(self, item);
1048 self.current_item = orig_current_item;
1051 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1052 if let hir::ExprKind::Struct(qpath, fields, ref base) = expr.kind {
1053 let res = self.typeck_results().qpath_res(qpath, expr.hir_id);
1054 let adt = self.typeck_results().expr_ty(expr).ty_adt_def().unwrap();
1055 let variant = adt.variant_of_res(res);
1056 if let Some(base) = *base {
1057 // If the expression uses FRU we need to make sure all the unmentioned fields
1058 // are checked for privacy (RFC 736). Rather than computing the set of
1059 // unmentioned fields, just check them all.
1060 for (vf_index, variant_field) in variant.fields.iter().enumerate() {
1063 .find(|f| self.typeck_results().field_index(f.hir_id) == vf_index);
1064 let (use_ctxt, span) = match field {
1065 Some(field) => (field.ident.span, field.span),
1066 None => (base.span, base.span),
1068 self.check_field(use_ctxt, span, adt, variant_field, true);
1071 for field in fields {
1072 let use_ctxt = field.ident.span;
1073 let index = self.typeck_results().field_index(field.hir_id);
1074 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1079 intravisit::walk_expr(self, expr);
1082 fn visit_pat(&mut self, pat: &'tcx hir::Pat<'tcx>) {
1083 if let PatKind::Struct(ref qpath, fields, _) = pat.kind {
1084 let res = self.typeck_results().qpath_res(qpath, pat.hir_id);
1085 let adt = self.typeck_results().pat_ty(pat).ty_adt_def().unwrap();
1086 let variant = adt.variant_of_res(res);
1087 for field in fields {
1088 let use_ctxt = field.ident.span;
1089 let index = self.typeck_results().field_index(field.hir_id);
1090 self.check_field(use_ctxt, field.span, adt, &variant.fields[index], false);
1094 intravisit::walk_pat(self, pat);
1098 ////////////////////////////////////////////////////////////////////////////////////////////
1099 /// Type privacy visitor, checks types for privacy and reports violations.
1100 /// Both explicitly written types and inferred types of expressions and patterns are checked.
1101 /// Checks are performed on "semantic" types regardless of names and their hygiene.
1102 ////////////////////////////////////////////////////////////////////////////////////////////
1104 struct TypePrivacyVisitor<'tcx> {
1106 maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
1107 current_item: LocalDefId,
1111 impl<'tcx> TypePrivacyVisitor<'tcx> {
1112 /// Gets the type-checking results for the current body.
1113 /// As this will ICE if called outside bodies, only call when working with
1114 /// `Expr` or `Pat` nodes (they are guaranteed to be found only in bodies).
1116 fn typeck_results(&self) -> &'tcx ty::TypeckResults<'tcx> {
1117 self.maybe_typeck_results
1118 .expect("`TypePrivacyVisitor::typeck_results` called outside of body")
1121 fn item_is_accessible(&self, did: DefId) -> bool {
1122 self.tcx.visibility(did).is_accessible_from(self.current_item, self.tcx)
1125 // Take node-id of an expression or pattern and check its type for privacy.
1126 fn check_expr_pat_type(&mut self, id: hir::HirId, span: Span) -> bool {
1128 let typeck_results = self.typeck_results();
1129 let result: ControlFlow<()> = try {
1130 self.visit(typeck_results.node_type(id))?;
1131 self.visit(typeck_results.node_substs(id))?;
1132 if let Some(adjustments) = typeck_results.adjustments().get(id) {
1133 adjustments.iter().try_for_each(|adjustment| self.visit(adjustment.target))?;
1139 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1140 let is_error = !self.item_is_accessible(def_id);
1142 self.tcx.sess.emit_err(ItemIsPrivate { span: self.span, kind, descr: descr.into() });
1148 impl<'tcx> Visitor<'tcx> for TypePrivacyVisitor<'tcx> {
1149 type NestedFilter = nested_filter::All;
1151 /// We want to visit items in the context of their containing
1152 /// module and so forth, so supply a crate for doing a deep walk.
1153 fn nested_visit_map(&mut self) -> Self::Map {
1157 fn visit_mod(&mut self, _m: &'tcx hir::Mod<'tcx>, _s: Span, _n: hir::HirId) {
1158 // Don't visit nested modules, since we run a separate visitor walk
1159 // for each module in `effective_visibilities`
1162 fn visit_nested_body(&mut self, body: hir::BodyId) {
1163 let old_maybe_typeck_results =
1164 self.maybe_typeck_results.replace(self.tcx.typeck_body(body));
1165 let body = self.tcx.hir().body(body);
1166 self.visit_body(body);
1167 self.maybe_typeck_results = old_maybe_typeck_results;
1170 fn visit_generic_arg(&mut self, generic_arg: &'tcx hir::GenericArg<'tcx>) {
1172 hir::GenericArg::Type(t) => self.visit_ty(t),
1173 hir::GenericArg::Infer(inf) => self.visit_infer(inf),
1174 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1178 fn visit_ty(&mut self, hir_ty: &'tcx hir::Ty<'tcx>) {
1179 self.span = hir_ty.span;
1180 if let Some(typeck_results) = self.maybe_typeck_results {
1182 if self.visit(typeck_results.node_type(hir_ty.hir_id)).is_break() {
1186 // Types in signatures.
1187 // FIXME: This is very ineffective. Ideally each HIR type should be converted
1188 // into a semantic type only once and the result should be cached somehow.
1189 if self.visit(rustc_hir_analysis::hir_ty_to_ty(self.tcx, hir_ty)).is_break() {
1194 intravisit::walk_ty(self, hir_ty);
1197 fn visit_infer(&mut self, inf: &'tcx hir::InferArg) {
1198 self.span = inf.span;
1199 if let Some(typeck_results) = self.maybe_typeck_results {
1200 if let Some(ty) = typeck_results.node_type_opt(inf.hir_id) {
1201 if self.visit(ty).is_break() {
1205 // We don't do anything for const infers here.
1208 bug!("visit_infer without typeck_results");
1210 intravisit::walk_inf(self, inf);
1213 fn visit_trait_ref(&mut self, trait_ref: &'tcx hir::TraitRef<'tcx>) {
1214 self.span = trait_ref.path.span;
1215 if self.maybe_typeck_results.is_none() {
1216 // Avoid calling `hir_trait_to_predicates` in bodies, it will ICE.
1217 // The traits' privacy in bodies is already checked as a part of trait object types.
1218 let bounds = rustc_hir_analysis::hir_trait_to_predicates(
1221 // NOTE: This isn't really right, but the actual type doesn't matter here. It's
1222 // just required by `ty::TraitRef`.
1223 self.tcx.types.never,
1226 for (trait_predicate, _, _) in bounds.trait_bounds {
1227 if self.visit_trait(trait_predicate.skip_binder()).is_break() {
1232 for (poly_predicate, _) in bounds.projection_bounds {
1233 let pred = poly_predicate.skip_binder();
1234 let poly_pred_term = self.visit(pred.term);
1235 if poly_pred_term.is_break()
1236 || self.visit_projection_ty(pred.projection_ty).is_break()
1243 intravisit::walk_trait_ref(self, trait_ref);
1246 // Check types of expressions
1247 fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) {
1248 if self.check_expr_pat_type(expr.hir_id, expr.span) {
1249 // Do not check nested expressions if the error already happened.
1253 hir::ExprKind::Assign(_, rhs, _) | hir::ExprKind::Match(rhs, ..) => {
1254 // Do not report duplicate errors for `x = y` and `match x { ... }`.
1255 if self.check_expr_pat_type(rhs.hir_id, rhs.span) {
1259 hir::ExprKind::MethodCall(segment, ..) => {
1260 // Method calls have to be checked specially.
1261 self.span = segment.ident.span;
1262 if let Some(def_id) = self.typeck_results().type_dependent_def_id(expr.hir_id) {
1263 if self.visit(self.tcx.type_of(def_id)).is_break() {
1269 .delay_span_bug(expr.span, "no type-dependent def for method call");
1275 intravisit::walk_expr(self, expr);
1278 // Prohibit access to associated items with insufficient nominal visibility.
1280 // Additionally, until better reachability analysis for macros 2.0 is available,
1281 // we prohibit access to private statics from other crates, this allows to give
1282 // more code internal visibility at link time. (Access to private functions
1283 // is already prohibited by type privacy for function types.)
1284 fn visit_qpath(&mut self, qpath: &'tcx hir::QPath<'tcx>, id: hir::HirId, span: Span) {
1285 let def = match qpath {
1286 hir::QPath::Resolved(_, path) => match path.res {
1287 Res::Def(kind, def_id) => Some((kind, def_id)),
1290 hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => self
1291 .maybe_typeck_results
1292 .and_then(|typeck_results| typeck_results.type_dependent_def(id)),
1294 let def = def.filter(|(kind, _)| {
1297 DefKind::AssocFn | DefKind::AssocConst | DefKind::AssocTy | DefKind::Static(_)
1300 if let Some((kind, def_id)) = def {
1301 let is_local_static =
1302 if let DefKind::Static(_) = kind { def_id.is_local() } else { false };
1303 if !self.item_is_accessible(def_id) && !is_local_static {
1304 let name = match *qpath {
1305 hir::QPath::LangItem(it, ..) => {
1306 self.tcx.lang_items().get(it).map(|did| self.tcx.def_path_str(did))
1308 hir::QPath::Resolved(_, path) => Some(self.tcx.def_path_str(path.res.def_id())),
1309 hir::QPath::TypeRelative(_, segment) => Some(segment.ident.to_string()),
1311 let kind = kind.descr(def_id);
1312 let sess = self.tcx.sess;
1313 let _ = match name {
1315 sess.emit_err(ItemIsPrivate { span, kind, descr: (&name).into() })
1317 None => sess.emit_err(UnnamedItemIsPrivate { span, kind }),
1323 intravisit::walk_qpath(self, qpath, id);
1326 // Check types of patterns.
1327 fn visit_pat(&mut self, pattern: &'tcx hir::Pat<'tcx>) {
1328 if self.check_expr_pat_type(pattern.hir_id, pattern.span) {
1329 // Do not check nested patterns if the error already happened.
1333 intravisit::walk_pat(self, pattern);
1336 fn visit_local(&mut self, local: &'tcx hir::Local<'tcx>) {
1337 if let Some(init) = local.init {
1338 if self.check_expr_pat_type(init.hir_id, init.span) {
1339 // Do not report duplicate errors for `let x = y`.
1344 intravisit::walk_local(self, local);
1347 // Check types in item interfaces.
1348 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1349 let orig_current_item = mem::replace(&mut self.current_item, item.owner_id.def_id);
1350 let old_maybe_typeck_results = self.maybe_typeck_results.take();
1351 intravisit::walk_item(self, item);
1352 self.maybe_typeck_results = old_maybe_typeck_results;
1353 self.current_item = orig_current_item;
1357 impl<'tcx> DefIdVisitor<'tcx> for TypePrivacyVisitor<'tcx> {
1358 fn tcx(&self) -> TyCtxt<'tcx> {
1365 descr: &dyn fmt::Display,
1366 ) -> ControlFlow<Self::BreakTy> {
1367 if self.check_def_id(def_id, kind, descr) {
1370 ControlFlow::CONTINUE
1375 ///////////////////////////////////////////////////////////////////////////////
1376 /// Obsolete visitors for checking for private items in public interfaces.
1377 /// These visitors are supposed to be kept in frozen state and produce an
1378 /// "old error node set". For backward compatibility the new visitor reports
1379 /// warnings instead of hard errors when the erroneous node is not in this old set.
1380 ///////////////////////////////////////////////////////////////////////////////
1382 struct ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1384 effective_visibilities: &'a EffectiveVisibilities,
1386 // Set of errors produced by this obsolete visitor.
1387 old_error_set: HirIdSet,
1390 struct ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1391 inner: &'a ObsoleteVisiblePrivateTypesVisitor<'b, 'tcx>,
1392 /// Whether the type refers to private types.
1393 contains_private: bool,
1394 /// Whether we've recurred at all (i.e., if we're pointing at the
1395 /// first type on which `visit_ty` was called).
1396 at_outer_type: bool,
1397 /// Whether that first type is a public path.
1398 outer_type_is_public_path: bool,
1401 impl<'a, 'tcx> ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1402 fn path_is_private_type(&self, path: &hir::Path<'_>) -> bool {
1403 let did = match path.res {
1404 Res::PrimTy(..) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::Err => {
1407 res => res.def_id(),
1410 // A path can only be private if:
1411 // it's in this crate...
1412 if let Some(did) = did.as_local() {
1413 // .. and it corresponds to a private type in the AST (this returns
1414 // `None` for type parameters).
1415 match self.tcx.hir().find(self.tcx.hir().local_def_id_to_hir_id(did)) {
1416 Some(Node::Item(_)) => !self.tcx.visibility(did).is_public(),
1417 Some(_) | None => false,
1424 fn trait_is_public(&self, trait_id: LocalDefId) -> bool {
1425 // FIXME: this would preferably be using `exported_items`, but all
1426 // traits are exported currently (see `EmbargoVisitor.exported_trait`).
1427 self.effective_visibilities.is_directly_public(trait_id)
1430 fn check_generic_bound(&mut self, bound: &hir::GenericBound<'_>) {
1431 if let hir::GenericBound::Trait(ref trait_ref, _) = *bound {
1432 if self.path_is_private_type(trait_ref.trait_ref.path) {
1433 self.old_error_set.insert(trait_ref.trait_ref.hir_ref_id);
1438 fn item_is_public(&self, def_id: LocalDefId) -> bool {
1439 self.effective_visibilities.is_reachable(def_id) || self.tcx.visibility(def_id).is_public()
1443 impl<'a, 'b, 'tcx, 'v> Visitor<'v> for ObsoleteCheckTypeForPrivatenessVisitor<'a, 'b, 'tcx> {
1444 fn visit_generic_arg(&mut self, generic_arg: &'v hir::GenericArg<'v>) {
1446 hir::GenericArg::Type(t) => self.visit_ty(t),
1447 hir::GenericArg::Infer(inf) => self.visit_ty(&inf.to_ty()),
1448 hir::GenericArg::Lifetime(_) | hir::GenericArg::Const(_) => {}
1452 fn visit_ty(&mut self, ty: &hir::Ty<'_>) {
1453 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = ty.kind {
1454 if self.inner.path_is_private_type(path) {
1455 self.contains_private = true;
1456 // Found what we're looking for, so let's stop working.
1460 if let hir::TyKind::Path(_) = ty.kind {
1461 if self.at_outer_type {
1462 self.outer_type_is_public_path = true;
1465 self.at_outer_type = false;
1466 intravisit::walk_ty(self, ty)
1469 // Don't want to recurse into `[, .. expr]`.
1470 fn visit_expr(&mut self, _: &hir::Expr<'_>) {}
1473 impl<'a, 'tcx> Visitor<'tcx> for ObsoleteVisiblePrivateTypesVisitor<'a, 'tcx> {
1474 type NestedFilter = nested_filter::All;
1476 /// We want to visit items in the context of their containing
1477 /// module and so forth, so supply a crate for doing a deep walk.
1478 fn nested_visit_map(&mut self) -> Self::Map {
1482 fn visit_item(&mut self, item: &'tcx hir::Item<'tcx>) {
1484 // Contents of a private mod can be re-exported, so we need
1485 // to check internals.
1486 hir::ItemKind::Mod(_) => {}
1488 // An `extern {}` doesn't introduce a new privacy
1489 // namespace (the contents have their own privacies).
1490 hir::ItemKind::ForeignMod { .. } => {}
1492 hir::ItemKind::Trait(.., bounds, _) => {
1493 if !self.trait_is_public(item.owner_id.def_id) {
1497 for bound in bounds.iter() {
1498 self.check_generic_bound(bound)
1502 // Impls need some special handling to try to offer useful
1503 // error messages without (too many) false positives
1504 // (i.e., we could just return here to not check them at
1505 // all, or some worse estimation of whether an impl is
1506 // publicly visible).
1507 hir::ItemKind::Impl(ref impl_) => {
1508 // `impl [... for] Private` is never visible.
1509 let self_contains_private;
1510 // `impl [... for] Public<...>`, but not `impl [... for]
1511 // Vec<Public>` or `(Public,)`, etc.
1512 let self_is_public_path;
1514 // Check the properties of the `Self` type:
1516 let mut visitor = ObsoleteCheckTypeForPrivatenessVisitor {
1518 contains_private: false,
1519 at_outer_type: true,
1520 outer_type_is_public_path: false,
1522 visitor.visit_ty(impl_.self_ty);
1523 self_contains_private = visitor.contains_private;
1524 self_is_public_path = visitor.outer_type_is_public_path;
1527 // Miscellaneous info about the impl:
1529 // `true` iff this is `impl Private for ...`.
1530 let not_private_trait = impl_.of_trait.as_ref().map_or(
1531 true, // no trait counts as public trait
1533 if let Some(def_id) = tr.path.res.def_id().as_local() {
1534 self.trait_is_public(def_id)
1536 true // external traits must be public
1541 // `true` iff this is a trait impl or at least one method is public.
1543 // `impl Public { $( fn ...() {} )* }` is not visible.
1545 // This is required over just using the methods' privacy
1546 // directly because we might have `impl<T: Foo<Private>> ...`,
1547 // and we shouldn't warn about the generics if all the methods
1548 // are private (because `T` won't be visible externally).
1549 let trait_or_some_public_method = impl_.of_trait.is_some()
1550 || impl_.items.iter().any(|impl_item_ref| {
1551 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1552 match impl_item.kind {
1553 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..) => self
1554 .effective_visibilities
1555 .is_reachable(impl_item_ref.id.owner_id.def_id),
1556 hir::ImplItemKind::Type(_) => false,
1560 if !self_contains_private && not_private_trait && trait_or_some_public_method {
1561 intravisit::walk_generics(self, &impl_.generics);
1563 match impl_.of_trait {
1565 for impl_item_ref in impl_.items {
1566 // This is where we choose whether to walk down
1567 // further into the impl to check its items. We
1568 // should only walk into public items so that we
1569 // don't erroneously report errors for private
1570 // types in private items.
1571 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1572 match impl_item.kind {
1573 hir::ImplItemKind::Const(..) | hir::ImplItemKind::Fn(..)
1574 if self.item_is_public(impl_item.owner_id.def_id) =>
1576 intravisit::walk_impl_item(self, impl_item)
1578 hir::ImplItemKind::Type(..) => {
1579 intravisit::walk_impl_item(self, impl_item)
1586 // Any private types in a trait impl fall into three
1588 // 1. mentioned in the trait definition
1589 // 2. mentioned in the type params/generics
1590 // 3. mentioned in the associated types of the impl
1592 // Those in 1. can only occur if the trait is in
1593 // this crate and will have been warned about on the
1594 // trait definition (there's no need to warn twice
1595 // so we don't check the methods).
1597 // Those in 2. are warned via walk_generics and this
1599 intravisit::walk_path(self, tr.path);
1601 // Those in 3. are warned with this call.
1602 for impl_item_ref in impl_.items {
1603 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1604 if let hir::ImplItemKind::Type(ty) = impl_item.kind {
1610 } else if impl_.of_trait.is_none() && self_is_public_path {
1611 // `impl Public<Private> { ... }`. Any public static
1612 // methods will be visible as `Public::foo`.
1613 let mut found_pub_static = false;
1614 for impl_item_ref in impl_.items {
1616 .effective_visibilities
1617 .is_reachable(impl_item_ref.id.owner_id.def_id)
1618 || self.tcx.visibility(impl_item_ref.id.owner_id).is_public()
1620 let impl_item = self.tcx.hir().impl_item(impl_item_ref.id);
1621 match impl_item_ref.kind {
1622 AssocItemKind::Const => {
1623 found_pub_static = true;
1624 intravisit::walk_impl_item(self, impl_item);
1626 AssocItemKind::Fn { has_self: false } => {
1627 found_pub_static = true;
1628 intravisit::walk_impl_item(self, impl_item);
1634 if found_pub_static {
1635 intravisit::walk_generics(self, &impl_.generics)
1641 // `type ... = ...;` can contain private types, because
1642 // we're introducing a new name.
1643 hir::ItemKind::TyAlias(..) => return,
1645 // Not at all public, so we don't care.
1646 _ if !self.item_is_public(item.owner_id.def_id) => {
1653 // We've carefully constructed it so that if we're here, then
1654 // any `visit_ty`'s will be called on things that are in
1655 // public signatures, i.e., things that we're interested in for
1657 intravisit::walk_item(self, item);
1660 fn visit_generics(&mut self, generics: &'tcx hir::Generics<'tcx>) {
1661 for predicate in generics.predicates {
1663 hir::WherePredicate::BoundPredicate(bound_pred) => {
1664 for bound in bound_pred.bounds.iter() {
1665 self.check_generic_bound(bound)
1668 hir::WherePredicate::RegionPredicate(_) => {}
1669 hir::WherePredicate::EqPredicate(eq_pred) => {
1670 self.visit_ty(eq_pred.rhs_ty);
1676 fn visit_foreign_item(&mut self, item: &'tcx hir::ForeignItem<'tcx>) {
1677 if self.effective_visibilities.is_reachable(item.owner_id.def_id) {
1678 intravisit::walk_foreign_item(self, item)
1682 fn visit_ty(&mut self, t: &'tcx hir::Ty<'tcx>) {
1683 if let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = t.kind {
1684 if self.path_is_private_type(path) {
1685 self.old_error_set.insert(t.hir_id);
1688 intravisit::walk_ty(self, t)
1691 fn visit_variant(&mut self, v: &'tcx hir::Variant<'tcx>) {
1692 if self.effective_visibilities.is_reachable(v.def_id) {
1693 self.in_variant = true;
1694 intravisit::walk_variant(self, v);
1695 self.in_variant = false;
1699 fn visit_field_def(&mut self, s: &'tcx hir::FieldDef<'tcx>) {
1700 let vis = self.tcx.visibility(s.def_id);
1701 if vis.is_public() || self.in_variant {
1702 intravisit::walk_field_def(self, s);
1706 // We don't need to introspect into these at all: an
1707 // expression/block context can't possibly contain exported things.
1708 // (Making them no-ops stops us from traversing the whole AST without
1709 // having to be super careful about our `walk_...` calls above.)
1710 fn visit_block(&mut self, _: &'tcx hir::Block<'tcx>) {}
1711 fn visit_expr(&mut self, _: &'tcx hir::Expr<'tcx>) {}
1714 ///////////////////////////////////////////////////////////////////////////////
1715 /// SearchInterfaceForPrivateItemsVisitor traverses an item's interface and
1716 /// finds any private components in it.
1717 /// PrivateItemsInPublicInterfacesVisitor ensures there are no private types
1718 /// and traits in public interfaces.
1719 ///////////////////////////////////////////////////////////////////////////////
1721 struct SearchInterfaceForPrivateItemsVisitor<'tcx> {
1723 item_def_id: LocalDefId,
1724 /// The visitor checks that each component type is at least this visible.
1725 required_visibility: ty::Visibility,
1726 has_old_errors: bool,
1730 impl SearchInterfaceForPrivateItemsVisitor<'_> {
1731 fn generics(&mut self) -> &mut Self {
1732 for param in &self.tcx.generics_of(self.item_def_id).params {
1734 GenericParamDefKind::Lifetime => {}
1735 GenericParamDefKind::Type { has_default, .. } => {
1737 self.visit(self.tcx.type_of(param.def_id));
1740 // FIXME(generic_const_exprs): May want to look inside const here
1741 GenericParamDefKind::Const { .. } => {
1742 self.visit(self.tcx.type_of(param.def_id));
1749 fn predicates(&mut self) -> &mut Self {
1750 // N.B., we use `explicit_predicates_of` and not `predicates_of`
1751 // because we don't want to report privacy errors due to where
1752 // clauses that the compiler inferred. We only want to
1753 // consider the ones that the user wrote. This is important
1754 // for the inferred outlives rules; see
1755 // `src/test/ui/rfc-2093-infer-outlives/privacy.rs`.
1756 self.visit_predicates(self.tcx.explicit_predicates_of(self.item_def_id));
1760 fn bounds(&mut self) -> &mut Self {
1761 self.visit_predicates(ty::GenericPredicates {
1763 predicates: self.tcx.explicit_item_bounds(self.item_def_id),
1768 fn ty(&mut self) -> &mut Self {
1769 self.visit(self.tcx.type_of(self.item_def_id));
1773 fn check_def_id(&mut self, def_id: DefId, kind: &str, descr: &dyn fmt::Display) -> bool {
1774 if self.leaks_private_dep(def_id) {
1775 self.tcx.emit_spanned_lint(
1776 lint::builtin::EXPORTED_PRIVATE_DEPENDENCIES,
1777 self.tcx.hir().local_def_id_to_hir_id(self.item_def_id),
1778 self.tcx.def_span(self.item_def_id.to_def_id()),
1779 FromPrivateDependencyInPublicInterface {
1781 descr: descr.into(),
1782 krate: self.tcx.crate_name(def_id.krate),
1787 let Some(local_def_id) = def_id.as_local() else {
1791 let vis = self.tcx.local_visibility(local_def_id);
1792 if !vis.is_at_least(self.required_visibility, self.tcx) {
1793 let hir_id = self.tcx.hir().local_def_id_to_hir_id(local_def_id);
1794 let vis_descr = match vis {
1795 ty::Visibility::Public => "public",
1796 ty::Visibility::Restricted(vis_def_id) => {
1797 if vis_def_id == self.tcx.parent_module(hir_id) {
1799 } else if vis_def_id.is_top_level_module() {
1806 let span = self.tcx.def_span(self.item_def_id.to_def_id());
1807 if self.has_old_errors
1809 || self.tcx.resolutions(()).has_pub_restricted
1811 let vis_span = self.tcx.def_span(def_id);
1812 if kind == "trait" {
1813 self.tcx.sess.emit_err(InPublicInterfaceTraits {
1817 descr: descr.into(),
1821 self.tcx.sess.emit_err(InPublicInterface {
1825 descr: descr.into(),
1830 self.tcx.emit_spanned_lint(
1831 lint::builtin::PRIVATE_IN_PUBLIC,
1834 PrivateInPublicLint { vis_descr, kind, descr: descr.into() },
1842 /// An item is 'leaked' from a private dependency if all
1843 /// of the following are true:
1844 /// 1. It's contained within a public type
1845 /// 2. It comes from a private crate
1846 fn leaks_private_dep(&self, item_id: DefId) -> bool {
1847 let ret = self.required_visibility.is_public() && self.tcx.is_private_dep(item_id.krate);
1849 debug!("leaks_private_dep(item_id={:?})={}", item_id, ret);
1854 impl<'tcx> DefIdVisitor<'tcx> for SearchInterfaceForPrivateItemsVisitor<'tcx> {
1855 fn tcx(&self) -> TyCtxt<'tcx> {
1862 descr: &dyn fmt::Display,
1863 ) -> ControlFlow<Self::BreakTy> {
1864 if self.check_def_id(def_id, kind, descr) {
1867 ControlFlow::CONTINUE
1872 struct PrivateItemsInPublicInterfacesChecker<'tcx> {
1874 old_error_set_ancestry: LocalDefIdSet,
1877 impl<'tcx> PrivateItemsInPublicInterfacesChecker<'tcx> {
1881 required_visibility: ty::Visibility,
1882 ) -> SearchInterfaceForPrivateItemsVisitor<'tcx> {
1883 SearchInterfaceForPrivateItemsVisitor {
1885 item_def_id: def_id,
1886 required_visibility,
1887 has_old_errors: self.old_error_set_ancestry.contains(&def_id),
1892 fn check_assoc_item(
1895 assoc_item_kind: AssocItemKind,
1896 vis: ty::Visibility,
1898 let mut check = self.check(def_id, vis);
1900 let (check_ty, is_assoc_ty) = match assoc_item_kind {
1901 AssocItemKind::Const | AssocItemKind::Fn { .. } => (true, false),
1902 AssocItemKind::Type => (self.tcx.impl_defaultness(def_id).has_value(), true),
1904 check.in_assoc_ty = is_assoc_ty;
1905 check.generics().predicates();
1911 pub fn check_item(&mut self, id: ItemId) {
1913 let def_id = id.owner_id.def_id;
1914 let item_visibility = tcx.local_visibility(def_id);
1915 let def_kind = tcx.def_kind(def_id);
1918 DefKind::Const | DefKind::Static(_) | DefKind::Fn | DefKind::TyAlias => {
1919 self.check(def_id, item_visibility).generics().predicates().ty();
1921 DefKind::OpaqueTy => {
1922 // `ty()` for opaque types is the underlying type,
1923 // it's not a part of interface, so we skip it.
1924 self.check(def_id, item_visibility).generics().bounds();
1927 let item = tcx.hir().item(id);
1928 if let hir::ItemKind::Trait(.., trait_item_refs) = item.kind {
1929 self.check(item.owner_id.def_id, item_visibility).generics().predicates();
1931 for trait_item_ref in trait_item_refs {
1932 self.check_assoc_item(
1933 trait_item_ref.id.owner_id.def_id,
1934 trait_item_ref.kind,
1938 if let AssocItemKind::Type = trait_item_ref.kind {
1939 self.check(trait_item_ref.id.owner_id.def_id, item_visibility).bounds();
1944 DefKind::TraitAlias => {
1945 self.check(def_id, item_visibility).generics().predicates();
1948 let item = tcx.hir().item(id);
1949 if let hir::ItemKind::Enum(ref def, _) = item.kind {
1950 self.check(item.owner_id.def_id, item_visibility).generics().predicates();
1952 for variant in def.variants {
1953 for field in variant.data.fields() {
1954 self.check(field.def_id, item_visibility).ty();
1959 // Subitems of foreign modules have their own publicity.
1960 DefKind::ForeignMod => {
1961 let item = tcx.hir().item(id);
1962 if let hir::ItemKind::ForeignMod { items, .. } = item.kind {
1963 for foreign_item in items {
1964 let vis = tcx.local_visibility(foreign_item.id.owner_id.def_id);
1965 self.check(foreign_item.id.owner_id.def_id, vis)
1972 // Subitems of structs and unions have their own publicity.
1973 DefKind::Struct | DefKind::Union => {
1974 let item = tcx.hir().item(id);
1975 if let hir::ItemKind::Struct(ref struct_def, _)
1976 | hir::ItemKind::Union(ref struct_def, _) = item.kind
1978 self.check(item.owner_id.def_id, item_visibility).generics().predicates();
1980 for field in struct_def.fields() {
1981 let field_visibility = tcx.local_visibility(field.def_id);
1982 self.check(field.def_id, min(item_visibility, field_visibility, tcx)).ty();
1986 // An inherent impl is public when its type is public
1987 // Subitems of inherent impls have their own publicity.
1988 // A trait impl is public when both its type and its trait are public
1989 // Subitems of trait impls have inherited publicity.
1991 let item = tcx.hir().item(id);
1992 if let hir::ItemKind::Impl(ref impl_) = item.kind {
1994 ty::Visibility::of_impl(item.owner_id.def_id, tcx, &Default::default());
1995 // check that private components do not appear in the generics or predicates of inherent impls
1996 // this check is intentionally NOT performed for impls of traits, per #90586
1997 if impl_.of_trait.is_none() {
1998 self.check(item.owner_id.def_id, impl_vis).generics().predicates();
2000 for impl_item_ref in impl_.items {
2001 let impl_item_vis = if impl_.of_trait.is_none() {
2003 tcx.local_visibility(impl_item_ref.id.owner_id.def_id),
2010 self.check_assoc_item(
2011 impl_item_ref.id.owner_id.def_id,
2023 pub fn provide(providers: &mut Providers) {
2024 *providers = Providers {
2026 effective_visibilities,
2027 check_private_in_public,
2033 fn visibility(tcx: TyCtxt<'_>, def_id: DefId) -> ty::Visibility<DefId> {
2034 local_visibility(tcx, def_id.expect_local()).to_def_id()
2037 fn local_visibility(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Visibility {
2038 match tcx.resolutions(()).visibilities.get(&def_id) {
2041 let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
2042 match tcx.hir().get(hir_id) {
2043 // Unique types created for closures participate in type privacy checking.
2044 // They have visibilities inherited from the module they are defined in.
2045 Node::Expr(hir::Expr { kind: hir::ExprKind::Closure{..}, .. })
2046 // - AST lowering creates dummy `use` items which don't
2047 // get their entries in the resolver's visibility table.
2048 // - AST lowering also creates opaque type items with inherited visibilities.
2049 // Visibility on them should have no effect, but to avoid the visibility
2050 // query failing on some items, we provide it for opaque types as well.
2051 | Node::Item(hir::Item {
2052 kind: hir::ItemKind::Use(_, hir::UseKind::ListStem)
2053 | hir::ItemKind::OpaqueTy(..),
2055 }) => ty::Visibility::Restricted(tcx.parent_module(hir_id)),
2056 // Visibilities of trait impl items are inherited from their traits
2057 // and are not filled in resolve.
2058 Node::ImplItem(impl_item) => {
2059 match tcx.hir().get_by_def_id(tcx.hir().get_parent_item(hir_id).def_id) {
2060 Node::Item(hir::Item {
2061 kind: hir::ItemKind::Impl(hir::Impl { of_trait: Some(tr), .. }),
2063 }) => tr.path.res.opt_def_id().map_or_else(
2065 tcx.sess.delay_span_bug(tr.path.span, "trait without a def-id");
2066 ty::Visibility::Public
2068 |def_id| tcx.visibility(def_id).expect_local(),
2070 _ => span_bug!(impl_item.span, "the parent is not a trait impl"),
2074 tcx.def_span(def_id),
2075 "visibility table unexpectedly missing a def-id: {:?}",
2083 fn check_mod_privacy(tcx: TyCtxt<'_>, module_def_id: LocalDefId) {
2084 // Check privacy of names not checked in previous compilation stages.
2086 NamePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id };
2087 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
2089 intravisit::walk_mod(&mut visitor, module, hir_id);
2091 // Check privacy of explicitly written types and traits as well as
2092 // inferred types of expressions and patterns.
2094 TypePrivacyVisitor { tcx, maybe_typeck_results: None, current_item: module_def_id, span };
2095 intravisit::walk_mod(&mut visitor, module, hir_id);
2098 fn effective_visibilities(tcx: TyCtxt<'_>, (): ()) -> &EffectiveVisibilities {
2099 // Build up a set of all exported items in the AST. This is a set of all
2100 // items which are reachable from external crates based on visibility.
2101 let mut visitor = EmbargoVisitor {
2103 effective_visibilities: tcx.resolutions(()).effective_visibilities.clone(),
2104 macro_reachable: Default::default(),
2105 prev_level: Some(Level::Direct),
2109 visitor.effective_visibilities.check_invariants(tcx, true);
2111 tcx.hir().walk_toplevel_module(&mut visitor);
2112 if visitor.changed {
2113 visitor.changed = false;
2118 visitor.effective_visibilities.check_invariants(tcx, false);
2120 let mut check_visitor =
2121 TestReachabilityVisitor { tcx, effective_visibilities: &visitor.effective_visibilities };
2122 tcx.hir().visit_all_item_likes_in_crate(&mut check_visitor);
2124 tcx.arena.alloc(visitor.effective_visibilities)
2127 fn check_private_in_public(tcx: TyCtxt<'_>, (): ()) {
2128 let effective_visibilities = tcx.effective_visibilities(());
2130 let mut visitor = ObsoleteVisiblePrivateTypesVisitor {
2132 effective_visibilities,
2134 old_error_set: Default::default(),
2136 tcx.hir().walk_toplevel_module(&mut visitor);
2138 let mut old_error_set_ancestry = HirIdSet::default();
2139 for mut id in visitor.old_error_set.iter().copied() {
2141 if !old_error_set_ancestry.insert(id) {
2144 let parent = tcx.hir().get_parent_node(id);
2152 // Check for private types and traits in public interfaces.
2153 let mut checker = PrivateItemsInPublicInterfacesChecker {
2155 // Only definition IDs are ever searched in `old_error_set_ancestry`,
2156 // so we can filter away all non-definition IDs at this point.
2157 old_error_set_ancestry: old_error_set_ancestry
2159 .filter_map(|hir_id| tcx.hir().opt_local_def_id(hir_id))
2163 for id in tcx.hir().items() {
2164 checker.check_item(id);